Rydberg : Studies on the Rocky Mountain Flora 509 



weaker, seldom over 5 mm. long, and the inner are acuminate, 

 wholly unarmed. The true C. Dniiinnoiidii, even in its subacaul- 

 escent state, has very broadly ovate outer bracts and the spine is 

 so fine that it is better called a bristle. The inner bracts have 2^ 

 long acuminate very crisp tip. In C. acaulcscois it is scarcely 

 crisped. The following specimens belong to C. acaiilcscciis : 



Utah : Bear River Valley, 1869, 5. JVatso/i, 6go. 



Wyoming: Woods Creek, 1897, Avcii Ne/soii, j^Sj. 



Colorado: Grizzly Creek, 1896, C. F. Baker. 



Carduus oreophilus sp. no v. 



Cirsium Dniiiniioiidii, D. C. Eaton, King's Rep. 5 : 195. 1871. 

 Not T. and G. 



Biennial stem 4-8 dm. high stout, angled and striate, slightly 

 arachnoid-hairy when young, leafy : basal leaves about 2 dm. 

 long, thin, short-petioled, green and glabrate above, more or less 

 grayish-tomentose beneath, pinnately lobed a little more than 

 half way to the midrib ; lobes triangular, usually 2-3 -lobed, with 

 rather slender spines 3— 10 mm. long: heads hemispherical, 2-2.5 

 cm. high, 2.5 cm. broad: outer and middle bracts narrowly lan- 

 ceolate, slightly arachnoid, tipped with flat spines i-d mm. long, 

 the inner with a long attenuate soft tip : flowers red. 



This species has been included in C. Dniinmoiidii but is taller 

 with smaller head, narrower bracts, the outer with longer spines, 

 and the tips of the inner scarcely crisp. It grows at an altitude of 

 I 500-3000 m. 



Colorado : Georgetown, 1895, P. A. Rydberg (type) ; Pagosa 

 Springs, 1899, ^- ^- I^o-kcr, 6^4.. 



Nevada: Run Valley, 1868, 5". Watsoi, 68g. 



Carduus griseus sp. nov. 



Biennial. Stem stout, sparingly floccose when young, angled 

 and striate : basal leaves oblanceolate in outline, thin, glabrate 

 above, grayish-tomentose beneath, deeply pinnately divided ; seg- 

 ments 3-4 cm. long, deeply 2-3 -lobed and toothed, tipped and 

 margined with rather slender spines 3-5 mm. long ; the upper 

 similar but less deeply divided, sessile and half clasping by the 

 dilated rounded shortly decurrent base : heads about 3 cm. high 

 and broad : bracts subequal, without dorsal glandular ridge, the 

 outer narrowly lanceolate, with a long-attenuate tip gradually 

 changing into a flat spine, and somewhat laciniate or spinulose- 



